linq to sql DAL

1. using System;
   using System.Collections.Generic;
   using System.Linq;
   using System.Text;
   using System.Data.Linq;

   namespace DAL
   {
   public class LinQBaseDao
   {
   /// <summary>
   /// 查询所有的记录
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <returns></returns>
   public IEnumerable<T> Query<T>(DataContext dc) where T:class
   {
   return dc.GetTable<T>().AsEnumerable<T>() ;
   }
   /// <summary>
   /// 按条件查询记录
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="fun"></param>
   /// <returns></returns>
   public IEnumerable<T> Query<T>(DataContext dc, Func<T,bool> fun) where T : class
   {
   return dc.GetTable<T>().Where<T>(fun).AsEnumerable<T>();
   }

   /// <summary>
   /// 查询单条 返回实体
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="fun"></param>
   /// <returns></returns>
   public T Single<T>(DataContext dc,Func<T, bool> fun) where T : class
   {
   return dc.GetTable<T>().Single<T>(fun);
   }

   /// <summary>
   /// 添加一条记录
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="tentity"></param>
   public void InsertOne<T>(DataContext dc, T tentity) where T : class
   {
   var table = dc.GetTable<T>();
   table.InsertOnSubmit(tentity);
   dc.SubmitChanges();
   }

   /// <summary>
   /// 添加多条记录
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="tentitys"></param>
   public void InsertToMany<T>(DataContext dc, IEnumerable<T> tentitys) where T : class
   {
   var table = dc.GetTable<T>();
   table.InsertAllOnSubmit(tentitys);
   dc.SubmitChanges();
   }

   /// <summary>
   /// 删除单条数据
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="tentity"></param>
   /// <param name="fun"></param>
   public void DeleteOne<T>(DataContext dc, T tentity, Func<T, bool> fun) where T : class
   {
   var table = dc.GetTable<T>();
   var result = table.Where<T>(fun).First<T>();
   table.DeleteOnSubmit(result);
   dc.SubmitChanges();
   }
   /// <summary>
   /// 按条件删除多条数据
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="tentitys"></param>
   /// <param name="fun"></param>
   public void DeleteToMany<T>(DataContext dc, IEnumerable<T> tentitys, Func<T, bool> fun) where T : class
   {
   var table = dc.GetTable<T>();
   var result = table.Where<T>(fun).AsEnumerable<T>();
   table.DeleteAllOnSubmit<T>(result);
   dc.SubmitChanges();
   }

   /// <summary>
   /// 删除多条数据
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="tentitys"></param>
   public void DeleteToManyByCondition<T>(DataContext dc, IEnumerable<T> tentitys) where T : class
   {
   var table = dc.GetTable<T>();
   table.DeleteAllOnSubmit<T>(tentitys);
   dc.SubmitChanges();
   }

   /// <summary>
   /// LINQ更新方法
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="dc"></param>
   /// <param name="fun"></param>
   /// <param name="tentity"></param>
   /// <param name="action"></param>
   public void Update<T>(DataContext dc, Func<T, bool> fun, T tentity, Action<T> action) where T : class
   {
   var table = dc.GetTable<T>().Single<T>(fun);
   //var table = dc.GetTable<T>().Where<T>(fun).Single<T>();
   action(table);
   dc.SubmitChanges();
   }
   }
   }